#include <stdio.h>

int main(void)
{
    printf("\n");
    int count, sum; /* 声明[1] */
    count = 0; /* 表达式语句 */
    sum = 0; /* 表达式语句 */
    while (count++ < 20) /* 迭代语句 */
        sum = sum + count;
    printf("sum = %d\n", sum); /* 表达式语句[2] */
    return 0;
}